Summary: This patch is the first effort to adding basic optimizations for FREEZE in SelDag.
Reviewers: spatel, lebedev.ri
Reviewed By: spatel
Subscribers: xbolva00, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76707
SelectionDAG CSEs nodes based on their result type and operands, but not their flags. The flags are expected to be intersected when they are CSEd. In SelectionDAGBuilder, for FP nodes we manage both the fast math flags and the nofpexcept flag after the nodes have already been CSEd when they were created with getNode. The management of the fastmath flags before the constrained nodes prevents the nofpexcept management from working correctly.
This commit moves the FMF handling for constrained intrinsics into their visitor and disables the common FMF handling for these nodes.
Differential Revision: https://reviews.llvm.org/D75224
Summary:
Using the default DAG.UnrollVectorOp on v16i8 and v8i16 vectors
results in i8 or i16 nodes being inserted into the SelectionDAG. Since
those are illegal types, this causes a legalization assertion failure
for some code patterns, as uncovered by PR45178. This change unrolls
shifts manually to avoid this issue by adding and using a new optional
EVT argument to DAG.ExtractVectorElements to control the type of the
extract_element nodes.
Reviewers: aheejin, dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, zzheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76043
Summary:
This patch adds the following intrinsics for non-temporal gather loads
and scatter stores:
* aarch64_sve_ldnt1_gather_index
* aarch64_sve_stnt1_scatter_index
These intrinsics implement the "scalar + vector of indices" addressing
mode.
As opposed to regular and first-faulting gathers/scatters, there's no
instruction that would take indices and then scale them. Instead, the
indices for non-temporal gathers/scatters are scaled before the
intrinsics are lowered to `ldnt1` instructions.
The new ISD nodes, GLDNT1_INDEX and SSTNT1_INDEX, are only used as
placeholders so that we can easily identify the cases implemented in
this patch in performGatherLoadCombine and performScatterStoreCombined.
Once encountered, they are replaced with:
* GLDNT1_INDEX -> SPLAT_VECTOR + SHL + GLDNT1
* SSTNT1_INDEX -> SPLAT_VECTOR + SHL + SSTNT1
The patterns for lowering ISD::SHL for scalable vectors (required by
this patch) were missing, so these are added too.
Reviewed By: sdesmalen
Differential Revision: https://reviews.llvm.org/D75601
As discussed in the commit thread for rGa253a2a and D73978, we can do more undef folding for FP ops.
The nnan and ninf fast-math-flags specify that if an operand is the disallowed value, the result is
poison, so we can produce an undef result.
But this doesn't work as expected (the undef operand cases remain) because of a Flags propagation
problem in SelectionDAGBuilder.
I've added DAGCombiner calls to enable these for the other cases because we've shown in other
patches that (because of the limited way that SDAG iterates), it is possible to miss simplifications
like this if they are done only at node creation time.
Several potential follow-ups to expand on this patch are possible.
Differential Revision: https://reviews.llvm.org/D75576
This is the second patch as part of https://bugs.llvm.org/show_bug.cgi?id=36544
Merging in the ConstantSDNode variant of FoldConstantArithmetic. After this, I will begin merging in FoldConstantVectorArithmetic
I've ensured this patch can build & pass all lit tests in Windows and Linux environments.
Patch by @justice_adams (Justice Adams)
Differential Revision: https://reviews.llvm.org/D74881
A question about this behavior came up on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2020-February/139003.html
...and as part of backend improvements in D73978.
We decided not to implement a more general change that would have
folded any FP binop with nearly arbitrary constant + undef operand
to undef because that is not theoretically correct (even if it is
practically correct).
This is the SDAG-equivalent to the IR change in D74713.
These are going to be useful in TargetLowering::SimplifyDemandedBits, so expose these helpers outside of SelectionDAG.cpp
Also add an getValidShiftAmountConstant early-out to getValidMinimumShiftAmountConstant/getValidMaximumShiftAmountConstant so we can use them for scalar cases as well.
Summary:
This was a very odd API, where you had to pass a flag into a zext
function to say whether the extended bits really were zero or not. All
callers passed in a literal true or false.
I think it's much clearer to make the function name reflect the
operation being performed on the value we're tracking (rather than on
the KnownBits Zero and One fields), so zext means the value is being
zero extended and new function anyext means the value is being extended
with unknown bits.
NFC.
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74482
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
Reviewers: courbet
Subscribers: arsenm, dschuff, jyknight, sdardis, nemanjai, jvesely, nhaehnle, sbc100, jgravelle-google, hiraditya, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73885
Summary:
A Copy with a source that is zeros is the same as a Set of zeros.
This fixes the invariant that SrcAlign should always be non-null.
Reviewers: courbet
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73791
Summary: This is a first step before changing the types to llvm::Align and introduce functions to ease client code.
Reviewers: courbet
Subscribers: arsenm, sdardis, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, jrtc27, atanasyan, jsji, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73785
and macro FUNCTION likewise. NFCI.
Some functions like fmuladd don't really have a node, we should divide
the declaration form those have node to avoid introducing fake nodes.
Differential Revision: https://reviews.llvm.org/D72871
Updated FoldConstantArithmetic method signature to match that of
FoldConstantVectorArithmetic in preparation for merging the two
functions together
https://bugs.llvm.org/show_bug.cgi?id=36544
This is the first step in combining the various
FoldConstantVectorArithmetic and FoldConstantVectorArithmetic
functions into one FoldConstantArithmetic function.
Differential Revision: https://reviews.llvm.org/D72870
Match the approach in SimplifyDemandedBits where we calculate the demanded elts and then have a common path for the ComputeKnownBits/ComputeNumSignBits call.
Match the approach in SimplifyDemandedBits/ComputeNumSignBits where we calculate the demanded elts and then have a common path for the ComputeKnownBits call.
Match the approach in SimplifyDemandedBits where we calculate the demanded elts and then have a common path for the ComputeKnownBits/ComputeNumSignBits call, additionally we only ever need original demanded elts of the base vector even if the index is unknown.
This patch also fixes up a number of cases in DAGCombine and
SelectionDAGBuilder where the size of a scalable vector is used in a
fixed-width context (thus triggering an assertion failure).
Reviewers: efriedma, c-rhodes, rovka, cameron.mcinally
Reviewed By: efriedma
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71215
In LLVM IR, vscale can be represented with an intrinsic. For some targets,
this is equivalent to the constexpr:
getelementptr <vscale x 1 x i8>, <vscale x 1 x i8>* null, i32 1
This can be used to propagate the value in CodeGenPrepare.
In ISel we add a node that can be legalized to one or more
instructions to materialize the runtime vector length.
This patch also adds SVE CodeGen support for VSCALE, which maps this
node to RDVL instructions (for scaled multiples of 16bytes) or CNT[HSD]
instructions (scaled multiples of 2, 4, or 8 bytes, respectively).
Reviewers: rengolin, cameron.mcinally, hfinkel, sebpop, SjoerdMeijer, efriedma, lattner
Reviewed by: efriedma
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68203
Add DemandedElts handling to ISD::ANY_EXTEND and add missing ISD::ANY_EXTEND_VECTOR_INREG handling. Despite the lack of test changes this code IS being used - its just that the ANY_EXTEND ops are legalized later on (typically to ZERO_EXTEND equivalents) so we typically manage to combine later on.
As mentioned by @nikic on rGef5debac4302, we can merge the guaranteed bottom zero bits from the shifted value, and then, if a min shift amount is known, zero out the bottom bits as well.
As mentioned by @nikic on rGef5debac4302 (although that was just about SHL), we can merge the guaranteed top zero bits from the shifted value, and then, if a min shift amount is known, zero out the top bits as well.
SHL tests / handling will be added in a follow up patch.
Summary:
be15dfa88f broke GlobalISel's usage of getSetCCInverse() which currently
appears to be limited to our out-of-tree backend. GlobalISel doesn't use
EVT's and isn't able to derive them from the information it has as it
doesn't distinguish between integer and floating point types (that
distinction is made by operations rather than values). Bring back the
bool version of getSetCCInverse() in a way that doesn't break the intent
of be15dfa88f but also allows GlobalISel to continue using it.
Reviewers: spatel, bogner, arichardson
Reviewed By: arichardson
Subscribers: rovka, hiraditya, Petar.Avramovic, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72309
As detailed in https://blog.regehr.org/archives/1709 we don't make use of the known leading/trailing zeros for shifted values in cases where we don't know the shift amount value.
This patch adds support to SelectionDAG::ComputeKnownBits to use KnownBits::countMinTrailingZeros and countMinLeadingZeros to set the minimum guaranteed leading/trailing known zero bits.
Differential Revision: https://reviews.llvm.org/D72573
This was increasing the number of instructions when fsub was legalized
on AMDGPU with no signed zeros enabled. This fold should be guarded by
hasOneUse, and I don't think getNode should be doing that. The same
fold is already done as a regular combine through isNegatibleForFree.
This does require duplicating, even though isNegatibleForFree does
this combine already (and properly checks hasOneUse) to avoid one PPC
regression. In the regression, the outer fneg has nsz but the fsub
operand does not. isNegatibleForFree only sees the operand, and
doesn't see it's used from a nsz context. A nsz parameter needs to be
added and threaded through isNegatibleForFree to avoid this.
SelectionDAG::transferDbgValues() can 'reattach' SDDbgValue from one to
another node, but doesn't change its source order. If the destination node has
the order greater than the SDDbgValue, there are two possible issues
revealed later:
* If debug info is attached to an instruction that is the first definition
of a register, this ends up with a def-after-use and the debug info
gets 'undef' later.
* If MIR has another definition of a register above the debug info,
the debug info may represent a source variable incorrectly because
it appears (significantly) before an instruction corresponded
to this debug info.
So, the patch changes the order of an SDDbgValue when it is moved
to a node with greater order.
Reviewers: dblaikie, jmorse, aprantl
Reviewed By: aprantl
Subscribers: aprantl, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71175
of integers to floating point.
This includes some of Craig Topper's changes for promotion support from
D71130.
Differential Revision: https://reviews.llvm.org/D69275
Summary:
This change is preparatory work to use this helper functions in more places.
In order to make this change, getMemBasePlusOffset() has been extended to
also take a SDNodeFlags parameter.
The motivation for this change is our out-of-tree CHERI backend
(https://github.com/CTSRD-CHERI/llvm-project). We use a separate register
type to store pointers (128-bit capabilities, which are effectively
unforgeable and monotonic fat pointers). These capabilities permit a
reduced set of operations and therefore use a separate ValueType (iFATPTR).
to represent pointers implemented as capabilities.
Therefore, we need to avoid using ISD::ADD for our patterns that operate
on pointers and need to use a function that chooses ISD::ADD or a new
ISD::PTRADD opcode depending on the value type.
We originally added a new DAG.getPointerAdd() function, but after this
patch series we can modify the implementation of getMemBasePlusOffset()
instead. Avoiding direct uses of ISD::ADD for pointer types will
significantly reduce the amount of assertion/instruction selection
failures for us in future upstream merges.
Reviewers: spatel
Reviewed By: spatel
Subscribers: merge_guards_bot, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71206
Guillaume Chatelet